Which contractor developed Twitter's first prototype with Jack Dorsey?

The contractor who developed Twitter’s first prototype with Jack Dorsey was Florian Weber.

The prototype was built in early 2006 while Dorsey and other Odeo employees were exploring a way to share short status updates through mobile-phone text messages. Weber worked as a contractor alongside Dorsey, and their early version was not initially a public social network. It served as an internal communication tool for Odeo employees, the staff of a podcasting company in San Francisco.

Twitter’s origins are often simplified into a story about four founders: Dorsey, Noah Glass, Biz Stone, and Evan Williams. Those figures were central to the company’s creation and business development, but they were not the contractor named in this question. Glass is especially easy to confuse with Weber because he played a major role in the early project and is often credited with helping shape its name and direction.

The service was first known internally and publicly as “twttr.” Dorsey posted the first message, “just setting up my twttr,” on March 21, 2006. A fuller version launched publicly on July 15 that year, before Twitter spun out into its own company in 2007.